U.S. Pat. No. 4,785,890 issued to Martin for “Ground-Driven Rotary Row Cleaner” illustrates prior art that may be relevant to the present disclosure, but that fails to teach the improvement disclosed and claimed herein. U.S. patents on several exemplary models of row cleaning wheels (U.S. Pat. No. 4,785,890) and closing wheels (U.S. Pat. No. 5,497,717) are incorporated by reference herein in their entirety. The operation of row planter units of the types disclosed in U.S. Pat. Nos. 4,009,668 and 6,148,747, both of which are incorporated by reference herein, is well known to those skilled in the art and not discussed in detail herein.